Rapid induction of false memory for pictures

Abstract

In this thesis, a new procedure is proposed which achieves the rapid induction of false recognition memory for rich pictorial stimuli. Chapter 2 presents the basic three-step procedure in which participants study some pictures, imagine others in response to words, and perform a picture recognition test. Imagining pictures leads to a false alarm rate of 27% above baseline (Experiments 1a and 1b). In Chapter 3, a source monitoring test is used to demonstrate that this effect is not solely due to diffuse familiarity (Experiment 2) and does not appear to be driven by perceptual processing (Experiment 3). Chapter 4 investigates whether imagination impairs discrimination between studied and new items presented side by side. On a two-alternative forced choice test, participants are less accurate in indicating the studied picture when it is paired with an imagined picture than when paired with a new picture (Experiment 4). The role of indirect tests in verbal false memory research and the value of applying them to pictorial stimuli is discussed in Chapter 5. An indirect perceptual identification test previously used for words is adapted to pictures and shown to be highly perceptually driven (Experiment 5). Chapter 6 presents consistent evidence for the lack of perceptual priming of imagined items in the current procedure despite high levels of false recognition (Experiments 6-7), again indicating that the effect is conceptually driven. Chapter 7 discusses how the new procedure presented in the thesis can further our understanding of the similarities and differences between true and false memories.